It is well-known in the medical arts that applying pressure to tissue helps during the healing process. Incised or torn soft tissue, for example, may be approximated with bandages, sutures, or staples. Proper and more rapid healing of broken or fractured bones likewise may be facilitated by applying constant pressure to the bone. For instance, physicians may insert pins, screws, or bolts in the area of the fracture in order to apply pressure to the fracture.
However, inserting screws through or around fractures can be complex and time-consuming. For example, the process of inserting a screw typically involves multiple steps conducted from multiple incisions or openings that provide access to the treated bone or tissue, including the steps of drilling holes, measuring the relevant distances to determine the appropriate screw selection, tapping the hole to establish threads, and screwing the screw into the hole.
In addition to the length and complexity of the process, bone screws also may lose their grip and strip out of the bone. In addition, currently available lag screws also typically provide only one side of cortex fixation and are generally not suited for percutaneous surgery. Moreover, when placing the screws in the bone, the physician may not accurately set the screw into the distal hole or may miss the distal hole completely, thereby resulting in the screw stripping the threads or breaking the bone.
Many devices and instruments have been disclosed to fasten soft and hard tissue for enhanced healing or tissue reconstruction. Examples of such devices include bone plates, bone wraps, external bone supports, and the like.
For example, U.S. Pat. No. 5,921,986, the contents of which are incorporated herein by reference, discloses a bone suture and associated methods for implantation and fracture fixation. The '986 Patent describes fasteners and anchors used in conjunction with an elongate fixation element, such as a suture. In some cases, it may be advantageous to use more rigid fixation elements.
Accordingly, a need exists for a tissue fixation instrument which can provide flexible or rigid fixation of tissue while accessing the tissue from a small skin portal.